Study of spin coated organic thin film under spectrophotometer

Thin films of organic compound Calix resorcinarene are deposited by spin coating method at different spinning speed and different concentrations. Films are studied under UV double beam spectrophotometer. Film thickness data are estimated from absorption spectra which peaks around 454 nm. Peak absorbances are found to be in consistent with spinning speed and solution concentration. The relation between film thickness h and spin speed omega obey power law relation of the form h proportional to omega(3/2). This is in agreement with the theoretical model of spin coating mechanism. Increasing solution concentration results in thicker film. This is presumably because of increased fluid viscosity.